Credit

Caption

Sperm whales (Physeter macrocephalus). The smaller whale (lower left) has remora (suckerfish) attached to it. These toothed whales are found in oceans worldwide. The male reaches an average of 16 metres in length, and can weigh over 45 tons. Females average 11 metres, while newborns are 4 metres long. Sperm whales can live for over 70 years. They are social animals, living in groups of around a dozen individuals. They feed on squid, octopus and fish, diving for over an hour to depths of 300 to 800 metres, sometimes as deep as 1-2 kilometres. Photographed off Mauritius, in the Indian Ocean.